This invention relates to data communications, and more particularly, to a method and apparatus employing a tape drive for transferring information between first and second devices, where at least one of the devices has the tape drive.
In recent years, computer tape drives have become increasingly popular for data transfer and back-up purposes. For example, the proliferation of Quarter-Inch Cartridge (QIC) tape technology has resulted in sales of millions of QIC tape drives, either as peripheral devices or as integral components of desktop or larger computers. Similarly, many other types of equipment, such as telecommunications switches, for example, are often manufactured with integral tape drives.
Due to their large data-storage capacities, QIC tape cartridges have been increasingly used to transfer data or software updates to host computers or devices having QIC tape drives. However, this requires significant human intervention, since the tape cartridge containing the data must be delivered by hand and manually inserted into the tape drive. The inherent delays in such a procedure are further aggravated where the host computer is situated in a distant location. Such delays also arise when data from such a host computer is required elsewhere.
One approach to a similar problem has been to provide a magnetic tape drive emulator to act as an imaging interface between a computer system and a peripheral image processing system. The magnetic tape drive emulator is physically connected to a tape drive interface bus, between a tape formatter and a tape drive system. However, such a physical connection is invasive to the hardware of the tape drive and its host computer, and may potentially be destructive to data. Government regulations may also limit the changes that can be made to equipment. Moreover, this procedure is inconvenient, particularly if the tape drive is an integral component of the host computer, in which case the host computer would have to be taken apart in order to connect the magnetic tape drive emulator to the tape drive bus.
Thus, there is a need for a convenient and non-invasive way to effect data communications between a host computer having a tape drive and a remote computer or device.
The present invention addresses the above need by providing an apparatus and method for using a tape drive for transferring information between first and second devices where the tape drive is included within at least one of the first and second devices. The apparatus and/or method allow a first device such as a host computer having a conventional tape drive to use the tape drive to achieve bidirectional or unidirectional data transfer between the host computer and a second device such as a remote computer, for example. This is accomplished by positioning a removable tape head interface adjacent the tape drive head, communicating signals between the tape drive head and the tape head interface, communicating signals between the tape head interface and the second device, and emulating a tape in the tape drive.
An apparatus for achieving this includes a tape head interface removably positionable adjacent the tape drive head to communicate with the tape drive head, a communications interface for communicating signals between the tape head interface and the second device, and a tape emulator in communication with the tape head interface for emulating a tape in the tape drive. The tape head interface preferably includes a transducer for transducing signals between the tape drive head and the tape head interface.
In one embodiment, the tape head interface has an outer housing shaped generally like a conventional tape cartridge, so that it is removably insertable into the conventional tape drive. A thin cable such as a flat ribbon cable is used to communicate signals between the tape head interface and the second device.
Once inserted into the conventional tape drive, the tape head interface mimics a tape cartridge. When the host computer attempts to read data from the tape, the tape head interface produces data signals which mimic the signals produced by a conventional magnetic tape, and which are received and interpreted by the tape drive as data on an actual tape. Conversely, when the host computer attempts to write to a tape, the data signals produced by the conventional tape drive head are received by the tape head interface and then communicated to the second device by any suitable data communication system which may include the public switched telephone network, for example.
Mimicking or emulating a tape in the tape drive, may include actuating tape position sensors in the tape drive to simulate tape position conditions. This may be achieved by use of a tape position indicator simulator, which in one embodiment directs radiation, such as light toward light sensors in the tape drive normally used for detecting holes punched in a tape.
In one embodiment, a tape drive movement detector is in communication with the tape head interface for detecting movement of a tape interface mechanism of the tape drive, and a processor circuit is in communication with the tape drive movement detector for controlling communication between the tape drive head and the tape head interface in response to signals received from the tape drive movement detector.
The processor circuit may be programmed to control the tape head interface to produce edge seek response signals for reception by the tape drive head when a first pre-defined position of the tape drive head relative to the tape head interface is detected by a tape drive head position detector.
In accordance with another aspect of the invention, there is provided an apparatus including a tape drive for communicating with a first device, a tape head interface removably positionable adjacent a tape drive head of the tape drive to communicate with the tape drive head, a communications interface in communication with the tape head interface for communicating signals between the tape head interface and a second device, and a tape emulator in communication with the tape head interface, for emulating a tape in the tape drive.
The present invention allows a host device to use a tape drive to achieve bidirectional or unidirectional data transfer with a remote device, without electrical connection to any part of the tape drive. Thus, the apparatus and method according to the embodiments of the invention, are non-invasive to existing hardware. Thus a tape cartridge or an apparatus according to an embodiment of the invention, can interchangeably be used in a conventional tape drive. Where the remote device is connected to a local or wide area network, the host computer or device is able to access an essentially unlimited amount of data through its tape drive, without the need to remove one tape cartridge and insert another. In this manner, periodic software updates may be uploaded from the network through the tape drive of the host computer, eliminating the need to manually deliver and insert a tape cartridge.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.